While the solar industry continues to grow, its long-term success depends on bringing down the cost of solar. Fortunately, there is a time-tested tool for reducing costs in growing industries: manufacturing science. I have spent the past nine years studying and implementing manufacturing-style processes including quality assurance and control (QA/QC) in solar and energy efficiency installation and operation. Recently, I have reviewed studies and interviewed stakeholders across virtually all segments of the solar industry, from manufacturers to installers. The problem is clear: solar quality across all segments of the industry is woefully poor. The EPC sector is no exception.

At the small contractor level, owner-operators believe that double-checking everything themselves is a sufficient quality measure. Among larger EPCs, quality is not managed systemically. While specifications are set, they are often not followed—especially when contractors change so frequently that managing quality measures is difficult, if not impossible. The proof is in the numbers—our internal estimates note between 30 to 50% of installations have quality issues, and between 15 to 20% have quality issues so severe as to be dangerous. This lack of adequate QA/QC costs EPCs money and exposes them to unacceptable risks. But it doesn’t have to be this way.

The science of quality found in today’s modern manufacturing settings is absolutely applicable to the solar installation process. Quality practices can be employed by EPCs and contractors of all sizes to mitigate the risks and costs associated with poor quality. In this article, we’ll cover a few tools solar contractors can use to improve solar installation quality on every project.

Measure the cost of poor quality

To understand how much poor quality is costing a contractor, it’s time to break out the spreadsheets and do a little simple math. For every repair line item, add up all the costs a firm has to absorb, from the time spent on the phone with a customer to the scheduling to the actual labor of rework and any hard costs incurred during the repairs. Also factor in cost of lost billable labor due to resources tied up fixing something a company can’t bill for. Use the results of these inspections in order to form accurate estimates.

Next, identify the number of times you have to roll a truck for this specific problem in comparison to the number of total installs, and do the math to see how much this specific problem is costing the company per year. For those who learn better by digging into the nuts and bolts of a spreadsheet, feel free to download Sustainabilist’s Cost of Poor Quality Worksheet Template.

Prioritize improvements using Pareto charts

As a contractor examines the failures they have data on, chances are they’ll start to see trends. These trends are the key to maximizing a company’s quality improvement efforts. Address the most costly and/or frequent quality issues first in order to make improvements as financially rewarding as possible as quickly as possible. Rather than just randomly deciding which problems to tackle, manufacturing science has a time-tested tool contractors can use: the Pareto chart

The Pareto chart is a simple tool that can help companies prioritize which improvements to focus on first. In addition, this chart will help contractors visualize the impact of fixing multiple quality issues. The process starts with a simple bar chart tallying how often each quality problem appears in the data. That chart is sorted from most frequent to least frequent. Next, a line chart is overlaid onto the chart representing the cumulative frequency of each problem in the series. For example, if a company has had 50 quality issues over the last year, with 15 calls for Problem A and 10 calls for Problem B, the cumulative impact of addressing both Problem A and Problem B would be 25 averted repair calls out of 50, or 50% of the total repair calls.

Pareto charts are relatively simple to make and the data can be easily downloaded to both Microsoft Excel and Google Sheets, among other platforms.

Develop a continuing education plan

Once a company has identified where problems are cropping up, it can make informed decisions about where to focus its training resources. Using the data, companies can design an ongoing training plan to address the problem areas where consistent failures are occurring. In this way, a company can continue to improve the knowledge and skill of its workforce where it counts—without wasting resources refreshing the team on tasks they’re performing well.

Make quality a core company value

Above and beyond any individual tools or tactics to improve quality, contractors can benefit greatly from making quality a central tenet of their business. By placing quality into your company’s work philosophy, all members of your team will go into any job with the goal of doing things right the first time. To take it even further, create a new quality manager position or carve out time in an existing employee’s schedule to take on the role of quality manager. While that prospect might seem daunting, there are numerous resources for quality improvement such as our upcoming webinar series. With even one employee focused on the question “How can we consistently improve quality?” enormous returns can be brought to a contractor’s bottom line.